Spindle mixer



FIG. 1 is a perspective view as seen from the top, front and right side of a spindle mixer showing the new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines shown in the drawing are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a spindle mixer, as shown and described. 